Astrophysical constraints on unparticle-inspired models of gravity

Eddington-inspired Born-Infeld gravity: astrophysical and cosmological constraints

In this letter we compute stringent astrophysical and cosmological constraints on a recently proposed Eddington-inspired Born-Infeld theory of gravity. We find, using a generalized version of the Zel'dovich approximation, that in this theory a pressureless cold dark matter fluid has a non-zero effective sound speed. We compute the corresponding effective Jeans length and show that it is approximately equal to the fundamental length of the theory $R_*=κ^{1/2} G^{-1/2}$, where $κ$ is the only additional parameter of theory with respect to general relativity and $G$ is the gravitational constant.…

White dwarfs in an ungravity-inspired model

An ungravity-inspired model is employed to examine the astrophysical parameters of white dwarf stars (WDs) using polytropic and degenerate gas approaches. Based on the observed properties such as mass, radius, and luminosity of selected WDs, namely, Sirius B and $ε$ Reticulum, bounds on the characteristic length and scaling dimension of the ungravity (UG) model are estimated. The UG effect on the Chandrasekhar limit for WDs is shown. The UG model is examined in the study of ultra-massive WDs, e.g., EUVE J1746-706. In the contact of UG inspired model, a new location for some WDs on the Hertzspr…

Hyperons in neutron stars within Eddington-inspired Born-Infeld theory of gravity

We investigate the mass-radius relation of neutron star (NS) with hyperons inside its core by using the Eddington-inspired Born-Infeld (EiBI) theory of gravity. The equation of state of the star is calculated by using the relativistic mean field model under which the standard SU(6) prescription and hyperons potential depths are used to determine the hyperon coupling constants. We found that, for $4\times 10^{6}~\rm{m^2}~\lesssim~κ\lesssim~6\times 10^{6}~\rm{m^2}$, the corresponding NS mass and radius predicted by the EiBI theory of gravity is compatible with observational constraints of maximu…

A stellar constraint on Eddington-inspired Born-Infeld gravity from cataclysmic variable binaries

Eddington-inspired Born-Infeld gravity is an important modification of Einstein's general relativity, which can give rise to non-singular cosmologies at the classical level, and avoid the end-stage singularity in a gravitational collapse process. In the Newtonian limit, this theory gives rise to a modified Poisson's equation, as a consequence of which stellar observables acquire model dependent corrections, compared to the ones computed in the low energy limit of general relativity. This can in turn be used to establish astrophysical constraints on the theory. Here, we obtain such a constraint…

迈向光谱基础模型：一种基于注意力机制的方法结合领域启发式微调与波长参数化

Toward a Spectral Foundation Model: An Attention-Based Approach with Domain-Inspired Fine-Tuning and Wavelength Parameterization

针对大规模恒星光谱巡天需求，提出基于注意力机制的光谱模拟器，结合领域特定微调与波长参数化技术，在O(1000)训练集上以5-10倍优势超越现有方法。

天体物理p过程中$^{113}$In上α诱发反应的实验研究

Experimental study of $α$-induced reactions on $^{113}$In for astrophysical $p$-process

本文通过叠层箔活化法测量$^{113}$In(α,γ)和(α,n)反应截面，结合统计模型计算确定α光学势等核输入参数，进而计算$^{113}$In与$^{117}$Sb间的反应率，以解释奇A p核$^{113}$In的丰度起源。